High Precision Spindle Ball Bearings

GRW: highest speed and great bearing capacity

GRW spindle ball bearings are suitable for applications, such as machine tools, requiring precision while carrying a high load capacity combined with high speed.

Spindle ball bearings are single-row angular contact ball bearings (separable ball bearings) with a nominal contact angle of 15° or 25°. They can be subjected to both radial and (in one direction) axial loads. The direction of the axial load carrying capacity is shown by a marking on the outer ring.

GRW spindle ball bearings are characterised by the following properties:

  • Manufacture in grade P4 (or ABEC7) or better
  • Rings generally made of corrosion-resistant SV30 high-grade steel
  • Steel or ceramic balls available for all types
  • Machined solid retainer of fiber-reinforced phenolic resin or special materials, for example for applications involving higher temperatures
    15° (C) or 25° (E) contact angle as a standard
  • Optionally, bearings can be paired with three pre-defined preload classes (L, M, S) or individual preload
  • Oil or grease lubrication
  • Open and closed versions available
  • Assembly, lubrication and packaging pursuant to cleanroom grade 10,000

Open spindle ball bearings

  • Standard version with large balls for optimum utilization of the bearing interior and solid retainer for high bearing capacity.
  • The outer ring has one shoulder only. The increased height of the snap feature prevents bearing collapse.
  • Solid retainer guided on outer ring with low cross-section, particularly well suited for oil injection lubrication.

Closed spindle ball bearings

  • The non-contact shields do not cause any additional friction torque
  • The standard shields made of Viton with metal stiffener offer excellent temperature and media resistance
  • Very narrow sealing gap for high dust protection
  • Recommended for grease lubrication, increases the longer service life
  • Same outer dimensions as open spindle bearings
  • This design requires often smaller balls, resulting in a lower bearing capacity but higher axial stiffness and speed limit (usually signified by an index letter after the basic type in the part number).
  • Also available without closure as high-speed version

Handling evidence:

  • Leave the bearing in its air-tight package until you are ready to start the assembly.
  • Ensure extreme cleanliness at the workplace.
  • Avoid shocks and impacts.
  • Axial load must only act on spindle bearings as indicated by the <s></s>marks on the outer ring.
  • Use suitable assembly tools to ensure that no assembly forces can be transferred through the balls.
  • Duplex bearings of pairing types -1 (DB), -2 (DF), -3 (DT) are always packed in pairs and can only be assembled in the specified arrangement with the other bearing in the package.
  • Universally matched bearings can be freely paired with each other, i.e. you may combine bearings from different packages or lots. These bearings may be assembled in any arrangement.
  • Before start of operation, allow the bearing to run in at high speed.